The influence of phosphodiesterase type 5 inhibitors on the human spermatozoids motility in vitro experiment

Phosphodiesterase type 5 inhibitors (iPDE-5) are the first line medications for erectile dysfunction in men. Given that all of them are highly selective, nevertheless they can have effects on the other isoforms of phosphodiesterase (including type 11), which are located in different tissues. Some experimental works show that influence on PDE-11 could affect spermatogenesis. Nevertheless, there is no common opinion whether fertility affected or not and how. In our study we have investigated in vitro influence of four available on market in Russia iPDE-5 (sildenafil, tadalafil, vardenafil, udenafil) on the motility of spermatozoids in 182 patients. Every sample of the ejaculate was split into control and experimental samples (control and study sample groups). In the study samples the influence of one of the four medications was investigated. Different concentrations of medications were selected for exposition with samples (sildenafil 25 and 250 ng/ml, tadalafil 100 ng/ml, vardenafil 50 ng/ml, udenafil 50 and 100 ng/ml). The estimation of the motility was made immediately after ejaculation and 1 and 3 hours thereafter. It was shown that sildenafil (25 ng/ml) and udenafil (50 ng/ml) in low concentration had a stimulatory effect on motility, while in high concentrations (250 and 100 ng/ml, correspondingly) they strongly suppress it. For tadalafil and vardenafil in selected concentrations the suppression effect on motility was shown.